The present invention relates to implantable articles and methods of implanting such articles. More particularly the invention relates to a bone prosthesis, prosthesis trial, instrument and method for implanting the same.
There are known to exist many designs for and methods for implanting implantable articles, such as bone prostheses. Such bone prostheses include components of artificial joints, such as elbows, hips, knees and shoulders.
One such implantable prosthesis is a shoulder prosthesis. During the life time of a patient, it may be necessary to perform a total shoulder replacement procedure on a patient as a result of, for example, disease or trauma, for example disease from osteoarthritis or rheumatoid arthritis. Currently, implantable shoulder prostheses include total shoulder prostheses and humeral head resurfacing replacement, as well as other devices. In a total shoulder replacement procedure, a humeral component having a head portion is utilized to replace the natural head portion of the upper arm bone or humerus. The humeral component typically has an elongated intermedullary stem, which is utilized to secure the humeral component to the patient's humerus. In such a total shoulder replacement procedure, the natural glenoid surface of the scapula is resurfaced or otherwise replaced with a glenoid component that provides a bearing surface for the head portion of the humeral component.
During arthroplasty, for example, a total shoulder replacement arthroplasty, the articulating surface, for example, the humeral head is removed as a first step, leaving an exposed resected surface. The steps in performing humeral joint arthroplasty includes having the surgeon ream the glenoid cavity. If the exposed bone is not well protected while the surgeon reams the glenoid cavity surface, or at other steps in the arthroplasty, the resected humerus may be damaged, resulting in unnecessary bone loss. The use of less invasive surgical procedures reduces the visibility to the resected surface and can lead to increased damage to the resected surface of the bone.
Attempts have been made to protect the resected surface of long bone. For example, osteotomy covers have been provided to be placed on the long bone. The prior art osteotomy protectors are round discs. The use of multiple sizes of the round discs are required to accommodate the wide variety in the size and shape of the resected surface of the long bone.
With only a few fixed round sizes, the surgeon is not able to cover the range of patient size necessary for full protection of the resected long bone. If the fixed sized protector is slightly smaller than the osteotomy surface, the outer cortical bone at the resected surface of the bone may be damaged or loss of bone may occur. If the fixed sized protector is slightly larger than the osteotomy surface, the protector may interfere with soft tissue surrounding the humerus or obstruct the surgeon from the preparing the glenoid. Such obstruction is more pronounced for minimally invasive surgeries where access and view of the surgical sight is more problematic.
The present invention attempts to overcome at least some of the aforementioned problems.